/**
 *
 * @author 
 *
 */
class md5 {
    public constructor() {

    }
    private hexcase = 0;   /* hex output format. 0 - lowercase; 1 - uppercase        */
    private b64pad = "";  /* base-64 pad character. "=" for strict RFC compliance   */

    /*
     * These are the privates you'll usually want to call
     * They take string arguments and return either hex or base-64 encoded strings
     */
    public hex_md5(s) { return this.rstr2hex(this.rstr_md5(this.str2rstr_utf8(s))); }
    private b64_md5(s) { return this.rstr2b64(this.rstr_md5(this.str2rstr_utf8(s))); }
    private any_md5(s,e) { return this.rstr2any(this.rstr_md5(this.str2rstr_utf8(s)),e); }
    private hex_hmac_md5(k,d)
    { return this.rstr2hex(this.rstr_hmac_md5(this.str2rstr_utf8(k),this.str2rstr_utf8(d))); }
    private b64_hmac_md5(k,d)
    { return this.rstr2b64(this.rstr_hmac_md5(this.str2rstr_utf8(k),this.str2rstr_utf8(d))); }
    private any_hmac_md5(k,d,e)
    { return this.rstr2any(this.rstr_hmac_md5(this.str2rstr_utf8(k),this.str2rstr_utf8(d)),e); }

    /*
     * Perform a simple self-test to see if the VM is working
     */
    private md5_vm_test() {
        return this.hex_md5("abc").toLowerCase() == "900150983cd24fb0d6963f7d28e17f72";
    }

    /*
     * Calculate the MD5 of a raw string
     */
    private rstr_md5(s) {
        return this.binl2rstr(this.binl_md5(this.rstr2binl(s),s.length * 8));
    }

    /*
     * Calculate the HMAC-MD5, of a key and some data (raw strings)
     */
    private rstr_hmac_md5(key,data) {
        var bkey = this.rstr2binl(key);
        if(bkey.length > 16) bkey = this.binl_md5(bkey,key.length * 8);

        var ipad = Array(16),opad = Array(16);
        for(var i = 0;i < 16;i++) {
            ipad[i] = bkey[i] ^ 0x36363636;
            opad[i] = bkey[i] ^ 0x5C5C5C5C;
        }

        var hash = this.binl_md5(ipad.concat(this.rstr2binl(data)),512 + data.length * 8);
        return this.binl2rstr(this.binl_md5(opad.concat(hash),512 + 128));
    }

    /*
     * Convert a raw string to a hex string
     */
    private rstr2hex(input) {
        try { this.hexcase } catch(e) { this.hexcase = 0; }
        var hex_tab = this.hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
        var output = "";
        var x;
        for(var i = 0;i < input.length;i++) {
            x = input.charCodeAt(i);
            output += hex_tab.charAt((x >>> 4) & 0x0F)
                + hex_tab.charAt(x & 0x0F);
        }
        return output;
    }

    /*
     * Convert a raw string to a base-64 string
     */
    private rstr2b64(input) {
        try { this.b64pad } catch(e) { this.b64pad = ''; }
        var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
        var output = "";
        var len = input.length;
        for(var i = 0;i < len;i += 3) {
            var triplet = (input.charCodeAt(i) << 16)
                | (i + 1 < len ? input.charCodeAt(i + 1) << 8 : 0)
                | (i + 2 < len ? input.charCodeAt(i + 2) : 0);
            for(var j = 0;j < 4;j++) {
                if(i * 8 + j * 6 > input.length * 8) output += this.b64pad;
                else output += tab.charAt((triplet >>> 6 * (3 - j)) & 0x3F);
            }
        }
        return output;
    }

    /*
     * Convert a raw string to an arbitrary string encoding
     */
    private rstr2any(input,encoding) {
        var divisor = encoding.length;
        var i,j,q,x,quotient;

        /* Convert to an array of 16-bit big-endian values, forming the dividend */
        var dividend = Array(Math.ceil(input.length / 2));
        for(i = 0;i < dividend.length;i++) {
            dividend[i] = (input.charCodeAt(i * 2) << 8) | input.charCodeAt(i * 2 + 1);
        }

        /*
         * Repeatedly perform a long division. The binary array forms the dividend,
         * the length of the encoding is the divisor. Once computed, the quotient
         * forms the dividend for the next step. All remainders are stored for later
         * use.
         */
        var full_length = Math.ceil(input.length * 8 /
            (Math.log(encoding.length) / Math.log(2)));
        var remainders = Array(full_length);
        for(j = 0;j < full_length;j++) {
            quotient = Array();
            x = 0;
            for(i = 0;i < dividend.length;i++) {
                x = (x << 16) + dividend[i];
                q = Math.floor(x / divisor);
                x -= q * divisor;
                if(quotient.length > 0 || q > 0)
                    quotient[quotient.length] = q;
            }
            remainders[j] = x;
            dividend = quotient;
        }

        /* Convert the remainders to the output string */
        var output = "";
        for(i = remainders.length - 1;i >= 0;i--)
            output += encoding.charAt(remainders[i]);

        return output;
    }

    /*
     * Encode a string as utf-8.
     * For efficiency, this assumes the input is valid utf-16.
     */
    private str2rstr_utf8(input) {
        var output = "";
        var i = -1;
        var x,y;

        while(++i < input.length) {
            /* Decode utf-16 surrogate pairs */
            x = input.charCodeAt(i);
            y = i + 1 < input.length ? input.charCodeAt(i + 1) : 0;
            if(0xD800 <= x && x <= 0xDBFF && 0xDC00 <= y && y <= 0xDFFF) {
                x = 0x10000 + ((x & 0x03FF) << 10) + (y & 0x03FF);
                i++;
            }

            /* Encode output as utf-8 */
            if(x <= 0x7F)
                output += String.fromCharCode(x);
            else if(x <= 0x7FF)
                output += String.fromCharCode(0xC0 | ((x >>> 6) & 0x1F),
                    0x80 | (x & 0x3F));
            else if(x <= 0xFFFF)
                output += String.fromCharCode(0xE0 | ((x >>> 12) & 0x0F),
                    0x80 | ((x >>> 6) & 0x3F),
                    0x80 | (x & 0x3F));
            else if(x <= 0x1FFFFF)
                output += String.fromCharCode(0xF0 | ((x >>> 18) & 0x07),
                    0x80 | ((x >>> 12) & 0x3F),
                    0x80 | ((x >>> 6) & 0x3F),
                    0x80 | (x & 0x3F));
        }
        return output;
    }

    /*
     * Encode a string as utf-16
     */
    private str2rstr_utf16le(input) {
        var output = "";
        for(var i = 0;i < input.length;i++)
            output += String.fromCharCode(input.charCodeAt(i) & 0xFF,
                (input.charCodeAt(i) >>> 8) & 0xFF);
        return output;
    }

    private str2rstr_utf16be(input) {
        var output = "";
        for(var i = 0;i < input.length;i++)
            output += String.fromCharCode((input.charCodeAt(i) >>> 8) & 0xFF,
                input.charCodeAt(i) & 0xFF);
        return output;
    }

    /*
     * Convert a raw string to an array of little-endian words
     * Characters >255 have their high-byte silently ignored.
     */
    private rstr2binl(input) {
        var output = Array(input.length >> 2);
        for(var i = 0;i < output.length;i++)
            output[i] = 0;
        for(var i = 0;i < input.length * 8;i += 8)
            output[i >> 5] |= (input.charCodeAt(i / 8) & 0xFF) << (i % 32);
        return output;
    }

    /*
     * Convert an array of little-endian words to a string
     */
    private binl2rstr(input) {
        var output = "";
        for(var i = 0;i < input.length * 32;i += 8)
            output += String.fromCharCode((input[i >> 5] >>> (i % 32)) & 0xFF);
        return output;
    }

    /*
     * Calculate the MD5 of an array of little-endian words, and a bit length.
     */
    private binl_md5(x,len) {
        /* append padding */
        x[len >> 5] |= 0x80 << ((len) % 32);
        x[(((len + 64) >>> 9) << 4) + 14] = len;

        var a = 1732584193;
        var b = -271733879;
        var c = -1732584194;
        var d = 271733878;

        for(var i = 0;i < x.length;i += 16) {
            var olda = a;
            var oldb = b;
            var oldc = c;
            var oldd = d;

            a = this.md5_ff(a,b,c,d,x[i + 0],7,-680876936);
            d = this.md5_ff(d,a,b,c,x[i + 1],12,-389564586);
            c = this.md5_ff(c,d,a,b,x[i + 2],17,606105819);
            b = this.md5_ff(b,c,d,a,x[i + 3],22,-1044525330);
            a = this.md5_ff(a,b,c,d,x[i + 4],7,-176418897);
            d = this.md5_ff(d,a,b,c,x[i + 5],12,1200080426);
            c = this.md5_ff(c,d,a,b,x[i + 6],17,-1473231341);
            b = this.md5_ff(b,c,d,a,x[i + 7],22,-45705983);
            a = this.md5_ff(a,b,c,d,x[i + 8],7,1770035416);
            d = this.md5_ff(d,a,b,c,x[i + 9],12,-1958414417);
            c = this.md5_ff(c,d,a,b,x[i + 10],17,-42063);
            b = this.md5_ff(b,c,d,a,x[i + 11],22,-1990404162);
            a = this.md5_ff(a,b,c,d,x[i + 12],7,1804603682);
            d = this.md5_ff(d,a,b,c,x[i + 13],12,-40341101);
            c = this.md5_ff(c,d,a,b,x[i + 14],17,-1502002290);
            b = this.md5_ff(b,c,d,a,x[i + 15],22,1236535329);

            a = this.md5_gg(a,b,c,d,x[i + 1],5,-165796510);
            d = this.md5_gg(d,a,b,c,x[i + 6],9,-1069501632);
            c = this.md5_gg(c,d,a,b,x[i + 11],14,643717713);
            b = this.md5_gg(b,c,d,a,x[i + 0],20,-373897302);
            a = this.md5_gg(a,b,c,d,x[i + 5],5,-701558691);
            d = this.md5_gg(d,a,b,c,x[i + 10],9,38016083);
            c = this.md5_gg(c,d,a,b,x[i + 15],14,-660478335);
            b = this.md5_gg(b,c,d,a,x[i + 4],20,-405537848);
            a = this.md5_gg(a,b,c,d,x[i + 9],5,568446438);
            d = this.md5_gg(d,a,b,c,x[i + 14],9,-1019803690);
            c = this.md5_gg(c,d,a,b,x[i + 3],14,-187363961);
            b = this.md5_gg(b,c,d,a,x[i + 8],20,1163531501);
            a = this.md5_gg(a,b,c,d,x[i + 13],5,-1444681467);
            d = this.md5_gg(d,a,b,c,x[i + 2],9,-51403784);
            c = this.md5_gg(c,d,a,b,x[i + 7],14,1735328473);
            b = this.md5_gg(b,c,d,a,x[i + 12],20,-1926607734);

            a = this.md5_hh(a,b,c,d,x[i + 5],4,-378558);
            d = this.md5_hh(d,a,b,c,x[i + 8],11,-2022574463);
            c = this.md5_hh(c,d,a,b,x[i + 11],16,1839030562);
            b = this.md5_hh(b,c,d,a,x[i + 14],23,-35309556);
            a = this.md5_hh(a,b,c,d,x[i + 1],4,-1530992060);
            d = this.md5_hh(d,a,b,c,x[i + 4],11,1272893353);
            c = this.md5_hh(c,d,a,b,x[i + 7],16,-155497632);
            b = this.md5_hh(b,c,d,a,x[i + 10],23,-1094730640);
            a = this.md5_hh(a,b,c,d,x[i + 13],4,681279174);
            d = this.md5_hh(d,a,b,c,x[i + 0],11,-358537222);
            c = this.md5_hh(c,d,a,b,x[i + 3],16,-722521979);
            b = this.md5_hh(b,c,d,a,x[i + 6],23,76029189);
            a = this.md5_hh(a,b,c,d,x[i + 9],4,-640364487);
            d = this.md5_hh(d,a,b,c,x[i + 12],11,-421815835);
            c = this.md5_hh(c,d,a,b,x[i + 15],16,530742520);
            b = this.md5_hh(b,c,d,a,x[i + 2],23,-995338651);

            a = this.md5_ii(a,b,c,d,x[i + 0],6,-198630844);
            d = this.md5_ii(d,a,b,c,x[i + 7],10,1126891415);
            c = this.md5_ii(c,d,a,b,x[i + 14],15,-1416354905);
            b = this.md5_ii(b,c,d,a,x[i + 5],21,-57434055);
            a = this.md5_ii(a,b,c,d,x[i + 12],6,1700485571);
            d = this.md5_ii(d,a,b,c,x[i + 3],10,-1894986606);
            c = this.md5_ii(c,d,a,b,x[i + 10],15,-1051523);
            b = this.md5_ii(b,c,d,a,x[i + 1],21,-2054922799);
            a = this.md5_ii(a,b,c,d,x[i + 8],6,1873313359);
            d = this.md5_ii(d,a,b,c,x[i + 15],10,-30611744);
            c = this.md5_ii(c,d,a,b,x[i + 6],15,-1560198380);
            b = this.md5_ii(b,c,d,a,x[i + 13],21,1309151649);
            a = this.md5_ii(a,b,c,d,x[i + 4],6,-145523070);
            d = this.md5_ii(d,a,b,c,x[i + 11],10,-1120210379);
            c = this.md5_ii(c,d,a,b,x[i + 2],15,718787259);
            b = this.md5_ii(b,c,d,a,x[i + 9],21,-343485551);

            a = this.safe_add(a,olda);
            b = this.safe_add(b,oldb);
            c = this.safe_add(c,oldc);
            d = this.safe_add(d,oldd);
        }
        return [a,b,c,d];
    }

    /*
     * These privates implement the four basic operations the algorithm uses.
     */
    private md5_cmn(q,a,b,x,s,t) {
        return this.safe_add(this.bit_rol(this.safe_add(this.safe_add(a,q),this.safe_add(x,t)),s),b);
    }
    private md5_ff(a,b,c,d,x,s,t) {
        return this.md5_cmn((b & c) | ((~b) & d),a,b,x,s,t);
    }
    private md5_gg(a,b,c,d,x,s,t) {
        return this.md5_cmn((b & d) | (c & (~d)),a,b,x,s,t);
    }
    private md5_hh(a,b,c,d,x,s,t) {
        return this.md5_cmn(b ^ c ^ d,a,b,x,s,t);
    }
    private md5_ii(a,b,c,d,x,s,t) {
        return this.md5_cmn(c ^ (b | (~d)),a,b,x,s,t);
    }

    /*
     * Add integers, wrapping at 2^32. This uses 16-bit operations internally
     * to work around bugs in some JS interpreters.
     */
    private safe_add(x,y) {
        var lsw = (x & 0xFFFF) + (y & 0xFFFF);
        var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
        return (msw << 16) | (lsw & 0xFFFF);
    }

    /*
     * Bitwise rotate a 32-bit number to the left.
     */
    private bit_rol(num,cnt) {
        return (num << cnt) | (num >>> (32 - cnt));
    }
}
